MSC Y4SEC-4005 5/8 x 5/8 4-Flute XL T-15 HSS Center Cut End Mill

This is a new MSC Y4SEC-4005 four-flute, center-cutting end mill in 5/8 in diameter with a 5/8 in shank, manufactured from T-15 high-speed steel — a cobalt-bearing, vanadium-rich HSS grade (nominally 5% Co, 5% V) offering superior hot hardness and wear resistance compared to M2 or M42. The tool carries a black oxide surface treatment, visible in the photos, which provides mild corrosion resistance and reduces friction during cutting. The extra-long (XL) flute length provides extended reach for deep-pocket milling, slotting, and profiling operations in steels, stainless steels, and other ferrous materials where T-15's elevated hot hardness outperforms standard cobalt grades. The Weldon-flat shank (clearly visible on the label and in photos) is compatible with standard Weldon-style end mill holders and set-screw toolholders accepting 5/8 in bore. The center-cutting geometry allows plunge milling as well as conventional peripheral and slot milling.

Product Specifications